Many drugs acting on the central nervous system such as anesthetics, hypnotics and anticonvulsants, probably act, in the first instance, on the lipid matrix of neuronal plasma membranes, secondarily on membrane proteins (e.g., the "sodium pump" proteins). These drugs (e.g., barbiturates, hydantoins, acylureids) usually posses a hydrophobic (lipophilic) part combined with a hydrophilic grouping of hydrogen bond acceptors (CO) and donors (NH). Combination of such groupings with semi-permanent membrane constituents, e.g., cholesterol or diglyceride residues, may lead to: 1) Direction of the pharmaceutically active grouping toward plasma membranes; 2) Prolongation of the effective life-times of drugs; 3) Possible reduction of toxicity; 4) Eventually, tailoring of drugs as to location of the active grouping in the hydrophobic-hydrophilic membrane boundary ("hydrogen belt") and as to arrangement of hydrogen bond donor and acceptor groups in membrane-perpendicular direction. To explore the potential of drug-anchoring, residues which are known to possess anticonvulsive potential, e.g., barbituric acid, hydantoin, carbamates, and substituted ureas, will be combined with cholestane or cholestene (delta 4 or delta 5) and diglyceride analogues. Synthesized compounds will be submitted to the Anticonvulsant Screening Project of the Antiepileptic Drug Development (ADD) Program of the National Institutes of Health.